As I recall, the original E-Cats were charged from a bottle source of hydrogen to 5-10 bar (depending on the activity he wished his experiment to show) while the device was still cold and then the gas input was valved off (producing a sealed reaction vessel). Since it was charged at about 300 Kelvin and subsequently heated to about 600 Kelvin, the operating pressure would be nearly double that.
The hotCat is different. Its operation has been primarily deduced from the Penon report and its pictures. The total "reactant" is contained between 2 coaxial stainless steel tubes sealed together by welding at each end - the result looking like a single piece of pipe. In between the two coaxial tubes Rossi's Metal powder+catalyst is inserted along with a charged metal hydride. Metal hydrides give off their hydrogen as the temperature increases and peak in hydrogen pressure output into a closed volume at about 30 bar. Above the temperature of peak output pressure, the pressure actually goes down. If I were Rossi, I would pick a hydride whose output pressure would peak near the max desired operating temperature of his reaction. That way if the temperature went hotter, the hydride would provide negative feedback by reducing the hydrogen pressure above its peak pressure temperature. In the hotCat HT2, Rossi filled the inside of the composite cylinder (pipe) with something more like his original recipe powder, and probably a different metal hydride. The ends of the HT2 are cold welded shut with plugs. The inner part is his "mouse" which I believe provides thermal gain beginning at a lower temperature. I posted drawings of these cross-sections. If you don't have them, I can post them again. It is interesting to speculate that the powder used in the hotCat portion may not even be a catalyzed Ni powder - it could be a more refractory metal, perhaps a titanium powder that has been catalytically activated. Rossi said that in his development he tried many powders besides Ni and found other recipes that worked, only they did not work as well as the catalyzed Ni powder. He could have gone back to one of those other chemistries to build the higher temperature hotCat. Bob Higgins On Sat, Sep 6, 2014 at 11:39 AM, Eric Walker <[email protected]> wrote: > > > About the H2 pressure and the mean free path of monoatomic hydrogen -- I'm > curious whether you've seen anything on the pressure in the E-Cat. I got > the impression along the way, probably from reading unrelated experimental > writeups, that the pressure need not be above ambient pressure, and that > the main thing additional pressure would accomplish would be to make > additional p (or d) available to the reaction sites. >
